Most likely Fentanyl. A very highly concentrated opiate that is very rarely ever perscribed for anything other than extreme rare pain mgnt situations or Hospice care for terminally ill. It should never be introduced directly into blood stream. Ive only ever seen it in a Patch form- similar to a nicotine patch- that allows it to be time released slowly and then absorbed through the skin and eventually indirectly into blood stream.

The problem comes when you have a scenario like my local area that finnaly admits theres an epidemic an attempts to quell by force rather than compassion. IMO. Stricter regulations make it harder to recieve pain pills on street, move to heroin and they nake it harder to get that... Force the dealers to take high powered opiates and cook then down to "cut" with lower grade heroin to boost profits... The end result is a bunch of addicts who have no idea what they are using, body vant process the high powered fentanyl and they overdose on what should have JUST been a normal fix. Its a sad situation all around. And more and morw common everyday- and ita not always JUST fentanyl, or even narcotics at all.